Ultimatelly, it doesn't matter what he used. He could've cause about the same amount of death with a .22 pistol and 7 round mags (one of the weapons used at Virgina Tech). He had all the time he wanted and calmly went from room to room, shooting each victim multiple times at point blank.

It does matter due to them attacking the AR-15 when you could literally go from door to door and confiscate every gun in the US and I would guarantee the next day there would be a shooting. The only people being hurt or affected by these new regulations is the law abiding citizen. Criminals don't care... Mentally unstable dont care... they will find a way to harm people if they really want to.